Sealed-type rolling bearing

ABSTRACT

A seal plate  8  is located between the outer ring  1  and inner ring  3 , and the outer diameter  11  side of the this seal plate  8  is fastened to the stationary ring  1 , and the lip  13  an the inner-diameter  12  side comes into sliding contact with or keeps a clearance with respect to the inner ring  3  to secure seal performance, and there is a protruding section  19  formed on the side surface  18  on the outside of the seal plate  8 , so that a clearance  29  is formed between the protruding section  19  and the peripheral part  25  near the bearing. Consequently, it is possible to provide a sealed-type rolling bearing where the seal performance is improved without increasing cost, by providing not only sealing in the lip portion but also sealing between the bearing and the peripheral part near the bearing.

FIELD OF THE INVENTION

The present invention is related to a sealed-type rolling bearing.

BACKGROUND OF THE INVENTION

For example, the conventional sealed-type rolling bearing maintained itsseal performance by lips 101, 102 that were formed on the inside andoutside on the inner-diameter surface of a seal plate (seal) 100.

Recently, it is desired for this kind of bearing that the sealperformance be improved without increasing the cost, and that thebearing adequately and precisely correspond to worsening operatingconditions.

However, with the convention bearing, when there is a lot of water ordirt around the bearing, there is a high possibility that the water ordirt will directly reach the lips 101, 102. In this case, it is thoughtthat the seal performance by just the lips 101, 102 will bedeteriorated.

Taking the problems with the prior art into consideration, the object ofthis invention is to provide a sealed-type rolling bearing that iscapable of not only sealing by the lips but also sealing between thebearing and the peripheral part near the bearing, and that improves theseal performance of the bearing without an increase in cost.

DISCLOSURE OF THE INVENTION

In order to accomplish the object described above, the technicalmeasures provided by this invention comprise a seal plate that islocated between the outer ring and inner ring, and where either theinner-diameter side or outer-diameter side of the this seal plate isfastened to the stationary ring, and the other maintains sealperformance by coming into sliding contact with the rotating ring orkeeping a clearance with respect to the rotating ring, and in whichthere is a protruding section formed on the side surface on the outsideof this seal plate, which forms a clearance between this protrudingsection and the peripheral part near the bearing.

In addition, the inner peripheral surface of this protruding sectionfaces the outer peripheral surface of the peripheral part near thebearing, forming the clearance therebetween.

Moreover, the sealed rolling bearing of this invention comprises: afirst seal plate between the outer ring and inner ring and a second sealplate facing the first seal plate, and either the inner-diameter side orthe outer-diameter side of this seal plate is fastened to the innerperipheral surface on the end of the outer ring, or to the outerperipheral surface on the end of the inner ring, and the other maintainsseal performance by coming in sliding contact with or forming aclearance with respect to the inner ring or outer ring; and the secondseal plate is fastened either to the inner peripheral surface on the endof the outer ring, or to the outer peripheral surface on the end of theinner ring, and where a protruding section is formed on the side surfaceon the outside of the first seal plate, and this protruding sectionforms a clearance between it and the second seal plate, such that theinner peripheral surface of the protruding section of the first sealplate faces the outer peripheral surface of the second seal plate toform the clearance between them.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partly cut-away, vertical cross-sectional drawing showingpart of an embodiment (first embodiment) of the present invention.

FIG. 2 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 3 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 4 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 5 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 6 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 7 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 8 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 9 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 10 is a partly cut-away, vertical cross-sectional drawing showingpart of another embodiment of the present invention.

FIG. 11 is a drawing showing the effect of a water-injection experimentof the present invention.

FIG. 12 is a vertical cross-sectional drawing showing the prior art.

The code numbers are as follows:

1: Outer ring, 3: Inner ring, 8: Seal plate, 11: Outer diameter, 12:Inner diameter

13: Lips, 14: First lip, 15: Second lip, 16: Third lip, 19: Protrudingsection,

25: Peripheral part near the bearing, 29: Clearance, 33: Inside surfaceof second seal plate, 34: Fourth lip

THE MOST PREFERRED EMBODIMENTS FOR WORKING THE INVENTION

Embodiments of the present invention will be explained below.

FIG. 1 shows a first embodiment, FIG. 2 shows a second embodiment, FIG.3 shows a third embodiment, FIG. 4 shows a fourth embodiment, FIG. 5shows a fifth embodiment, FIG. 6 shows a sixth embodiment, FIG. 11 is adrawing of the experiment results showing the effect of the presentinvention, FIG. 7 shows a seventh embodiment, FIG. 8 shows an eighthembodiment, FIG. 9 shows a ninth embodiment and FIG. 10 shows a tenthembodiment.

In the figures, 1 is the outer ring, 3 is inner ring, 7 are rollingbodies, 8 is the seal plate, and 25 are the peripheral part near thebearing.

The sealed-type roller bearing of this invention is suitable forapplication for electrical equipment of automobiles or the like,however, the range of the application of this invention is not limitedand can be applied to all kind of bearings such as for normal electricalequipment, small motors, etc.

In the embodiments of this invention, the construction of the outer ring1, inner ring 3, and rolling bodies 7 are not limited to theconstruction shown in the drawings, and generally used shapes andstructures can be adopted, so a detailed explanation of the constructionis omitted in this explanation of the present invention.

The explanation of this invention is particularly centered on the sealplate 8 and the peripheral part 25 near the bearing and the relationshipbetween them.

The seal plate 8 comprises a core member (made of metal or the like) 9that is covered by an elastic member (made of rubber, synthetic resin orthe like) 10 and formed such that it is generally circular, and whereeither the inner-diameter 12 side or outer-diameter 11 side is fastenedto the stationary ring 1 side, and the lip 13 formed on the othermaintains a seal performance by coming into sliding contact with or bykeeping a clearance with the rotating ring 3 side, and where aprotruding section 19 is formed on the side surface 18 on the outsidesuch that the protruding section 19 forms a clearance 29 between it andthe peripheral part 25 near the bearing.

In this embodiment of the invention, the outer-diameter 11 side isfastened by crimping or pressure fitting to the plate groove 2 in theouter ring (stationary ring) 1, and the plurality of lips 14, 15, 16that are formed on the inner-diameter 12 side make a seal by coming intosliding contact with plate groove 5 in the inner ring (rotating ring) 3or by forming a clearance 30 and labyrinth 31 with respect to the plategroove 5.

Moreover, a type of seal plate 8 without a core member 9 is also withinthe range of this invention.

There is one or a plurality of lips 13 (in this embodiment there arethree, a first lip 14 to a third lip 16) that are formed, and in thecase of there being just one lip 13, the lip is properly selected toface either inward or outward, and in the case of a plurality of lips,the lips are properly selected to face inward, outward or bothdirections, and part or all of them maintain a seal through slidingcontact or by forming a clearance and labyrinth.

It is possible to have just one lip 13, however by having a plurality oflips, as described above, even when the seal performance of one of thelip decreases, the other lips cover for it, thus making it possible tomaintain a seal performance over long period of time.

The construction of the lip 13, such as the shape, length, number oflips and whether the lip is a contact type or non-contact type is notlimited and can be properly changed within the range of the invention.

The protruding section 19 has a cross section with any desired shape,and it is formed such that it is continuous in the circumferentialdirection with the side surface 18 on the outside of the seal plate 8,and the position of the protrusion is such that there is a narrow gap(clearance) 29 formed in the circumferential direction between thesurface on the opposite end 22 and the end surface 26 of the peripheralpart 25 near the bearing.

The width of the aforementioned narrow gap (clearance) 29 is notparticularly limited and can be freely set within the range of theinvention.

The protruding section 19 is not particularly limited, however, in thisembodiment, the protruding section 19 is located such that the outeredge 23 of the opposing end surface 22 is substantially at the samelevel as the inner edge 27 of the end surface of the peripheral part 25near the bearing.

Moreover, the narrow gap (clearance) 29 formed between the protrudingsection 19 and the peripheral part 25 near the bearing prevents water ordirt from reaching the lip 13 side to secure and improve the sealperformance.

The shape of the protruding section 19 is not limited to the shape shownin the figures, and can be changed arbitrarily within the range of theinvention. For example, the shape is not limited to a rectangularcross-sectional shape, but a desired cross-sectional shape could beselected such as a square, semi-circular, or triangular cross-section.Moreover, the shape of the end surface of the opposing end 22 that facesthe part near the bearing is also not limited to the shape shown in thefigure, and could be an uneven shape with a stepped section.

Moreover, it is also possible to form a protruding section that iszig-zag shaped or waved shaped in the circumferential direction suchthat there is a difference between high and low points in the radialdirection, and such that there are a plurality of continuous protrudingsections provided concentric with each other.

Furthermore, forming the protruding section such that it is notcontinuous in the circumferential direction is also within the range ofthis invention.

The peripheral part 25 near the bearing may typically be a cover plateor stepped shaft, and any part that is capable of forming a narrow gap29 between its end surface (free end) 26 and the opposing end 22 of theseal plate 8 can be freely applied within the range of the invention.Also, in this invention, the slinger of the bearing is also included asthe peripheral part 25 near the bearing.

Furthermore, the narrow gap 29, that is formed between the end surface22 of the protruding section 19 and the end surface 26 of the peripheralpart 25 near the bearing, prevents water or dirt from getting into thebearing, and the water or dirt is guided outside along the outerperipheral surface of the protruding section 19, so is prevented fromgetting into area of the lip 13.

Next, the first through the sixth preferred embodiments of the inventionwill be further explained in detail.

First Embodiment

In this embodiment, the seal plate 8 comprises an inward facing firstlip (main lip) 14, second lip 15 and third lip 16 that are formed aroundits inner-diameter 12 side concentric with each other, and a protrudingsection 19 with a rectangular cross section that is formed around theside surface 18 on the outside of the seal plate 8 such that it iscontinuous in the circumferential direction.

The outer-periphery 11 of the seal plate 8 is crimped and fastened tothe outer-ring plate groove 2, and the inward facing first lip 14, whichis formed around the inner-diameter 12 side comes in contact (or it mayform a narrow gap without coming in contact) with the wall surface 6 ofthe plate groove 5 of the inner ring 3. The inward facing second lip 15is formed on the side surface on the inner side and has a largerdiameter than the first lip 14, and it forms a narrow gap 30 between itand the wall surface 6 (or it may come in contact with the wall surfaceof the plate groove). Furthermore, the inward facing third lip 16 isformed on the side surface on the inner side and has a larger diameterthan the second lip 15 and its surface 17 is continuous in thecircumferential direction and parallel with the outer-diameter surface 4of the inner ring 3 to form a labyrinth 31, so that the seal performanceis secured.

Also, the opposing end surface 22 of the protruding section 19 faces theend surface 26 of the peripheral part 25 near the bearing to form anarrow gap 29 that is continuous in the circumferential direction, andthis narrow gap 29 secures the seal performance by preventing water ordirt from entering in the direction of the lip 13.

The length of the protruding section 19 in the radial direction and theprotruding length in the outward direction are not limited to that shownin the figure, and can be changed freely within the range of theinvention.

Moreover, in this embodiment, the outer edge 23 of the opposing endsurface 22 of the protruding section 19 is on the same level as theinner edge 27 of the end surface 26 of the peripheral part 25 near thebearing, however it is not limited by this, and the outward protrusionlength of the protruding section 19 may be changed to move the outeredge 28 in the direction of the outer edge 28 of the end surface 26 ofthe peripheral part 25 near the bearing.

The construction of the first lip 14, second lip 15 and third lip 16,such as the shape, length and whether the lip is a contact type ornon-contact type is not limited to the illustrated examples and can beproperly changed within the range of the invention.

The narrow gap that is formed between the protruding section 19 and theperipheral part 25 near the bearing prevents surrounding water or dirtfrom getting inside, and the surrounding water or dirt is guided outsidealong the horizontal upper end surface 24 of the protruding section 19,so is prevented from getting into area of the lip 13, and thus the sealperformance is improved.

Furthermore, since a plurality of lips, that is first lip 14 to thirdlip 16, are used, even when the seal of one of the lips decreases, theother lips cover for it, thus making it possible to maintain a sealperformance over long period of time.

Second Embodiment

In this embodiment, only the construction of the protruding section 19has been changed and the rest of the construction is the same as in thefirst embodiment. The explanation of the construction and function onthe first embodiment is referred to and that for this embodiment isomitted here.

The outer surface 20 of the protruding section 19 is an inclinedsurface, and a narrow gap 29 that is continuous in the circumferentialdirection is formed between the opposing end surface 22 of theprotruding section 19 and the end surface 26 of the peripheral part 25near the bearing, and this narrow gap 29 secures the seal performance toprevent water or dirt from getting into the area of the lip 13.

Also, this narrow gap 29, that is formed between the protruding section19 and the peripheral part 25 near the bearing, prevents surroundingwater or dirt from getting inside, and the surrounding water or dirt isguided outside (direction of the arrow) along the inclined surface 20 ofthe protruding section 19, and is prevented from getting into area ofthe lip 13, and thus the seal performance is improved. The angle ofinclination of the inclined surface 20 of the protruding section 19 isnot particularly limited and can be freely selected.

The seal performance is secured by a plurality of lips, that is firstlip 14 to third lip 16, and is the same as the first embodiment.

A plurality of concentric, circular protruding sections 19 may beformed, and the clearance may be formed between the opposing end surfaceof the protruding section that is the closest to the inner diameter andthe end surface of the peripheral part near the bearing, which is withinthe range of this invention.

In this embodiment, the outer edge 23 of the opposing end surface 22 onthe protruding section 19 is on the same level as the inner edge 27 ofthe end surface 26 of the part near the bearing, however, the presentinvention is not limited to this, and the angle of inclination can bechanged such that this outer edge 23 is moved toward the direction ofthe outer edge 28 of the end surface 26 of the peripheral part 25 nearthe bearing.

Third Embodiment

In this embodiment, only the construction of the protruding section 19has been changed to be different from that of the first embodiment andthe rest of the construction is the same as in the first embodiment. Anexplanation of the construction and function of the first embodiment arereferred to, and that on this embodiment is omitted here.

The protruding section 19 has a square cross-sectional shape, and anarrow gap 29 that is continuous in the circumferential direction isformed between the opposing end surface 22 of the protruding section 19and the end surface 26 of the peripheral part 25 near the bearing, andwith this narrow gap 29, the seal performance is secured to preventwater or dirt from getting into the area of the lip 13.

Also, this narrow gap 29, that is formed between the protruding section19 and the peripheral part 25 near the bearing, prevents surroundingwater or dirt from getting inside, and the surrounding water or dirt isguided outside (in the direction of the arrow) on the horizontal upperend surface 24 of the protruding section 19, and is prevented fromgetting into area of the lip 13, and thus the seal performance isimproved.

Securing the seal performance by the plurality of lips, that is firstlip 14 to third lip 16, is the same as in the first embodiment.

The length in the radial direction of the protruding section 19 and theprotruding length outward, are not particularly limited to theillustrated example, and can be freely changed within the range of theinvention.

Moreover, in this embodiment, the outer edge 23 of the opposing endsurface 22 on the protruding section 19 is on the same level as theinner edge 27 of the end surface 26 of the peripheral part 25 near thebearing, however, the position is not limited to this, and theprotruding length can be changed such that this outer edge 23 is movedtoward the direction of the outer edge 28 of the end surface 26 of theperipheral part 25 near the bearing.

Fourth Embodiment

In this embodiment, the peripheral part 25 near the bearing is formed ina specific shape having a stepped shaft, and the other construction isthe same as in the first embodiment. The explanation of the constructionand functions of the first embodiment are referred to, and that on thepresent embodiment is omitted here. Also, the construction of thestepped shaft is not limited to that shown in the figure and a steppedshaft of other construction that is within the range of the inventioncan also be applied.

Fifth Embodiment

In this embodiment, the peripheral part 25 near the bearing is formed ina specific shape having a slinger, one of the bearing parts, and theother construction is the same as in the first embodiment. Theexplanation of the construction and functions of the first embodimentshall be referred to as, and those of this embodiment are omitted here.Also, the construction of the slinger is not limited to that shown inthe figure, and a slinger of other construction that is within the rangeof the invention can also be applied.

Sixth Embodiment

In this embodiment, similar to the fifth embodiment, a specific shape ofthe slinger for the peripheral part 25 near the bearing is used, andonly the assembly differs from the slinger of the fifth embodiment. Theother construction is the same as in the first embodiment. Theexplanation of the construction and functions of the first embodimentare referred to, and those of this embodiment are omitted here.Moreover, the construction of the slinger shown in the figure is just anexample as in the fifth embodiment.

Seventh Embodiment

In this embodiment, only the construction of the protruding section 19is different from the first embodiment, and the other construction isthe same as in the first embodiment. The explanation of the constructionand functions of the first embodiment are referred to, and that on thepresent embodiment is omitted here.

The protruding section 19 has a square cross-sectional shape, and anarrow gap 29 that is continuous in the circumferential direction isformed between the opposing end surface 22 of the protruding section 19and the end surface 26 of the peripheral part 25 near the bearing,and.with this narrow gap 29, the seal performance is secured to preventwater or dirt from getting into the area of the lip 13 by forming afirst labyrinth section with the narrow gap 29.

Also, this narrow gap 29, that is formed between the protruding section19 and the peripheral part 25 near the bearing, prevents surroundingwater or dirt from getting inside, and since the protruding section 19surrounds the outer surface 26 of a second seal plate to face it, thesurrounding water or dirt is prevented from getting into area of the lip13, and thus the seal performance is improved.

Securing the seal performance by the plurality of lips, that is firstlip 14 to third lip 16, is the same as in the first embodiment.

The length in the radial direction of the protruding section 19 and theprotruding length outward, are not particularly limited to theillustrated example, and can be freely changed within the range of theinvention.

Moreover, in this embodiment, when the clearance between the opposingend surface 22 of the protruding section 19 and the outer peripheralsurface 26 of the second seal plate is 0.2 mm±0.2 mm for an innerdiameter of the bearing between 8 mm and 20 mm, it is possible to havesufficient seal effects and to obtain a product which is stable inprocessing parts.

Eighth Embodiment

In this embodiment, only the construction of the second seal plate hasbeen changed, and the other construction is the same as in the seventhembodiment. The explanation of the construction and functions of theseventh embodiment shall be referred to, and that of the present exampleis omitted here.

The second seal plate 25 is fastened to the inner peripheral surface onthe end of the outer ring that faces the first seal plate, or outerperipheral surface on the end of the inner ring, so that it is notnecessary to change the prior art bearing dimensions. Therefore, thereis no need to change the design of the surrounding parts including themating parts, so there is no rise in cost and there is high flexibilityin its application. Moreover, no protrusion gets in the way whenhandling the bearing, so that handling is very convenient.

The narrow gap 29, that is formed between the protruding section 19 ofthe first seal plate and the second seal plate 25, prevents surroundingwater or dirt from getting inside, and since the protruding section 19surrounds the outer peripheral surface 26 of the second seal plate toface it, the surrounding water or dirt is prevented from getting intoarea of the lip 13, and thus the seal performance is improved.

Securing the seal performance by the plurality of lips, that is firstlip 14 to third lip 16, is the same as in the first embodiment.

Ninth Embodiment

In this embodiment, only the construction of the second seal plate hasbeen changed, and the other construction is the same as in the eighthembodiment. The explanation of the construction and functions of theeighth embodiment shall be referred to, and that of the present exampleis omitted here.

The outer dimension of the second seal plate 25 is made as large aspossible and still have space for the protruding section 19 of the firstseal plate to be constructed, so that the distance of the secondlabyrinth section, that is formed between the outside surface 18 of thefirst seal plate and the inside surface 33 of the second seal plate canbe made long.

Foreign matter is prevented from moving in the direction of the lip 13,thus the seal performance is further improved.

Securing the seal performance by the plurality of lips, that is firstlip 14 to third lip 16, is the same as in the first embodiment.

Tenth Embodiment

In this embodiment, only the construction of the first seal plate ischanged from that of the eight embodiment, and the other construction isthe same as in the eighth embodiment. The explanation of theconstruction and functions of the eighth embodiment shall be referredto, and that of the present example is omitted here.

The first seal plate 8 is fastened to the inner peripheral surface onthe end of the outer ring or to the outer peripheral surface on the endof the inner ring to face the second seal plate. Also, on the innerperipheral portion of the first seal plate there is a new outward facinglip, that is fourth lip section 34 that faces the second seal plate, andit forms a third labyrinth section between it and the inner peripheralsurface 33 of the second seal plate.

The labyrinth structure that is formed between the protruding section 19of the first seal plate and the second seal plate 25 is reinforced, sothat foreign matter is prevented from moving in the direction of the lip13, and the seal performance is further improved.

FIG. 11 is a drawing that uses a water injection test to explain theeffect of the invention. The performance of the seal was confirmed underthe following test conditions.

Test Conditions

Test bearing: OD 35 mm×ID 15 mm×W 14 mm

Axial load: 490 N

Radial load: 0 N

RPM: 1800 rpm

Injection conditions: 200 cc/min. From a distance 10 mm above toward thebearing seal surface.

Comparative example 1: Prior art seal construction (corresponds to theconstruction in FIG. 12)

Comparative example 2: The construction of comparative example 1 withthe second seal plate.

Example 1: Corresponds to the seventh embodiment.

Example 2: Corresponds to the tenth embodiment.

From the results of the water injection test, preventing water fromgetting inside is clearly improved, and when the fourth, outward facinglip is added to the first seal plate, extremely good seal performance isobtained.

In the first to the sixth embodiments described above, a bearing with astationary outer ring, and rotating inner ring was explained, however,the invention is not limited to this and the type with a rotating outerring and stationary inner ring is also within the range of thisinvention.

Industrial Application

This invention, constructed as described above, maintains the sealperformance by having either the inner-diameter side or outer-diameterside of the seal plate come in sliding contact with or forming aclearance with the rotating ring, and the protruding section on the sidesurface on the outside of the seal plate forms a clearance with theperipheral part near the bearing to prevent water and dirt from gettinginto the lip section through the clearance, so that it is possible toprovide a sealed-type rolling bearing with improved performance withoutincreasing the cost. Moreover, with the sealed-type rolling bearing ofthis invention, it is possible to obtain a sufficient and sure sealeffect even under conditions of large amounts of surrounding water anddirt.

What is claimed is:
 1. A sealed-type rolling bearing comprising: anouter ring and an inner ring having a side face, one of the outer andinner ring being stationary and the other being rotatable, a first sealplate having the inner-diameter side or outer-diameter side, said firstseal plate being located between the outer ring and inner ring on theaxially inside of the side face, either the inner-diameter side orouter-diameter side of the first seal plate being fastened to thestationary ring and the other maintaining seal performance by cominginto sliding contact with the rotating ring, a second seal plate locatedbetween the outer ring and the inner ring on the axially inside of theside face and on the axially outside of the first seal plate andfastened to the rotatable ring, and a protruding section formed on theaxially inside of the side surface on the axially outside of the firstseal plate, so that a clearance is formed between the protruding sectionand the second seal plate.
 2. The sealed-type rolling bearing of claim1, wherein the protruding section has an inner peripheral surface andthe second seal plate has an outer peripheral surface and wherein theclearance is formed therebetween.